#include <stdio.h>
int rec(int n){
if(n == 1){
return 3;
}
else if(n == 2){
return 0;
}
else if(n == 3){
return 2;
}
else{
return rec(n-2) + rec(n-3);
}
}
int main(void){
int n;
for(n = 1; n <= 50; n++){
}
return 0;
}
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